If your poker room is not supported in StackAndTile by default, or if one of the built-in sites is giving you trouble, then you can create your own configuration to support your own site.
Choose "Other" from the Sites dropdown to create your own custom site.
A wizard will start, follow the steps and save your config at the end.
(It will be saved in the /Sites sub-directory, such as
C:\Program Files (x86)\StackAndTile\Sites\. Similarly, if someone else creates a config using this tool, you should be able to share configs between users. All someone would need to do is to put the saved .ini file in their /Sites sub-directory, and then..)
Then return to the Sites tab inside StackAndTile, scroll to the bottom of the drop down list and you should find your new custom site listed there.
Then choose the site, and proceed to click on Include Site.
Keep in mind, that SaT will look for the fold/call/bet buttons on the poker table. If those buttons move around and do not always appear in the same location, things probably will not work.
Also, don't expect custom sites to work with the Free mode.